The history of Moldova can be traced to the 1350s, when the Principality of Moldavia, the medieval precursor of modern Moldova and Romania, was founded. The principality was a vassal of the Ottoman Empire from 1538 until the 19th century. In 1812, following one of several Russian-Turkish wars, the eastern half of the principality, Bessarabia, was annexed by the Russian Empire. In 1918, Bessarabia briefly became independent as the Moldavian Democratic Republic and, following the decision of the Parliament (Sfatul Țării), united with Romania. In 1940 it was annexed by the Soviet Union, joined to the Moldavian ASSR, and became the Moldavian Soviet Socialist Republic until the dissolution of the USSR. In 1991 the country declared independence as the Republic of Moldova.